Gun powders, solid rocket propellants and like particulate explosive materials are manufactured by methods which yield a product having a moisture content substantially higher than that ultimately desired. In the case of certain rocket propellants, for example, the moisture content can be as high as 70% or more by weight. The industry has therefore adopted various methods for drying explosive materials. Despite the fact that particulate explosive materials are especially sensitive to heat, most prior-art drying methods are thermal drying methods and have proved to be unduly dangerous. One such prior-art method, for example, subjects the moist explosive material to heat while the material is supported on an endless belt which conveys the material as it is being dried. Through a thermal drying method employing a conveyor belt may operate successfully for drying explosive materials for a prolonged period, the nature of the method and the equipment it employs is such as to promote unpredictable localized temperature build-ups which can cause fires and/or explosion of all the material being dried. The industry has accordingly continued to seek improved, safer methods for drying explosive materials.